Infections of the Kidney and Bladder
Victoria J. Sharp, MD
Department of Urology
First Published: January 2004
Last Revised: March 2006
Peer Review Status: Internally Peer Reviewed
A urinary tract infection (UTI) is a common infection which can involve any portion of the urinary system. The urinary system includes the kidneys (produce urine), ureters (tubes that carry the urine from the kidneys to the bladder), bladder (stores urine) and the urethra (the tube that carries urine from the bladder to outside the body).
UTIs can affect men and women, and all age groups. Most urinary tract infections are caused by bacteria, and the anal region is a common source for these organisms. Infections generally develop in the lower urinary tract (bladder and urethra), but can progress to involve the upper urinary tract (ureters and kidneys).
There are many factors which influence a person’s susceptibility to UTIs:
- women are more prone to develop UTIs due to their
- shorter urethra;
- sexual intercourse causes some women to develop UTIs for unknown reasons;
- women who use a diaphragm or spermicidal foam are at increased risk for developing UTIs;
- urinary catheterization (placement of a small tube in the urinary collecting system) can introduce bacteria into the urinary system;
- obstruction of the bladder outlet (prostate enlargement in men, bladder stones)
- injuries to the bladder that prevent it from functioning normally (spinal cord injuries);
- incomplete emptying of the bladder
Infections of the bladder are also called cystitis, and are the most common type of UTI. Common symptoms include:
- a need to urinate urgently and frequently
- a sensation of pain or burning with urination
- blood in the urine
- cloudy or foul smelling urine
- cramps or tenderness over the bladder
Kidney infections, also referred to as pyelonephritis, tend to be more severe. Patients may have symptoms similar to cystitis, but also may have:
- fever and chills
- tenderness over the kidneys (located on either side of the spinal column, above the waist)
- nausea and vomiting
The diagnosis of a UTI is made by examination of the urine with a dipstick and/or a microscope. The urine may also be cultured to determine the type of organism causing the infection. Depending on the scenario, your physician may order additional tests to study the urinary system.
UTIs are commonly treated with oral antibiotics; how long you need to take them depends on the severity of the infection. In general, bladder infections are treated for 3-7 days, while kidney infections are treated for 7-14 days, and may require intravenous antibiotics. If there are other factors increasing the risk for recurrent infections, these are often managed after the main infection is cleared. Preventive measures for recurrent infections include cranberry juice, vitamin C, and sometimes a small dose of antibiotic taken daily or after sexual intercourse.